90 likes | 246 Views
Pumping of Brackish and Saline Water in Coastal Aquifers: An Effective Tool for Alleviation of Seawater Intrusion. Mohsen Sherif Civil and Environmental Eng. Department College of Engineering, UAE University United Arab Emirates. Anvar Kacimov Department of Soils, Water and
E N D
Pumping of Brackish and Saline Water in Coastal Aquifers: An Effective Tool for Alleviation of Seawater Intrusion Mohsen Sherif Civil and Environmental Eng. Department College of Engineering, UAE University United Arab Emirates Anvar Kacimov Department of Soils, Water and Agricultural Engineering, SQU University Sultanate of Oman 23 June 2008
Seawater Intrusion into Coastal Aquifers Factors Affecting Seawater Intrusion • Type of aquifer and its geometry and geology • Water table and pizometric heads • Natural rates of flow • Irrigation and agricultural practices • Pumping and recharge events • Rainfall intensities and frequencies • Seawater concentration and density • Characteristics and parameters of the porous medium • Geometric and hydraulic boundaries • Tidal effects • Earthquakes and vibrational effects • Others Which of these factors are important? It depends on the problem
Mitigation of Seawater Intrusion • Inevitable process • Pumping activities and intrusion rates Measures to Control Seawater Intrusion • Reduce the pumping rates • Reallocation of pumping fields • Land use and agriculture practices • Artificial recharge of groundwater • Use of Scavenger wells
Objective and Study Domain • Examine the possibility of reducing seawater intrusion by pumping of saline (brackish) groundwater. 6 m (asl) 4 m (asl) 4000 elements (5.0 x 2.5 m) 4221 nodes 50 m H2 = 4 + k (50 –y) Hmax = 5.25 m 1000 m n = 0.25, kx = 10-6 m2, ky = 10-7 m2, α = 5 m ρf = 1000 kg/m3 , ρs = 1025 kg/m3
Tested Scenarios 6 m 4 m Steady State equi-concentration lines Run 1 140 m 105 m Steady State velocity vectors 5 m 4 m Reduced hydraulic head at the land side Run 2 277 m 196 m
Effect of Pumping 6 m 4 m Q1 Pumping 86 m3/d: Steady state Run 3 Q1 Q1 Pumping 86 m3/d from two locations at land and sea side boundaries: Steady state
Effect of Pumping Q1 Q2 4 m 6 m Q1 = 86 m3/d and Q2 = 130 m3/d Steady State equi-concentration lines Run 5
Pumping from a single well Basic Run Group 1 Run 1 Group 1 Run 2 Group 1 Run 3 Group 2 Run 4 Group 2 Run 6 Group 3 Run 7 Group 3 Run 8 Group 3 Run 9